Control device for vehicular opening/closing body

ABSTRACT

A control device for a vehicular opening/closing body is provided with a duty ratio calculator ( 78 ), which calculates a duty ratio when power supplied to a door drive motor ( 48 ) allowing an opening/closing body to open/close is subjected to duty control based on a result of adding first second multiplication values, the first multiplication value being obtained by multiplying a speed difference between a target opening/closing body speed and an actual opening/closing body speed by a negative proportional gain, and the second multiplication value being obtained by multiplying an integral value of the speed difference by an integral gain.

TECHNICAL FIELD

The present invention relates to a control device for a vehicularopening/closing body, which is provided in a vehicle and controls aspeed of the vehicular opening/closing body opening/closing, forexample, when an occupant gets on/off the vehicle.

BACKGROUND ART

Heretofore, a power slide door system has been known, which opens/closesa slide-type door mechanism provided in a vehicle by a drive force of amotor. This type of control device for opening/closing a vehicle slidedoor, which automatically opens/closes the vehicle slide door by drivingthe motor, is provided with a revolution number detection unit fordetecting a revolution number of the motor. A technology of calculatinga moving speed of the slide door based on a revolution number of themotor per predetermined time, which is detected by the revolution numberdetection unit, and of controlling the drive force of the motor, forexample, a duty ratio in a PWM (Pulse Width Modulation) control based onthe calculated moving speed of the slide door and a target moving speedis disclosed in Japanese Patent Laid-Open Publication 2000-127764.

In the technology described above, when the speed of the slide door islowered more than a determining speed VJ, which is lower than a targetspeed VL by a predetermined value, the fact that a state where the speedof the slide door is lowered more than the target speed VL by more thanthe predetermined value (VL-VJ) continues is represented by a count ofrotation pulse signals of the drive motor. Then, when the number of thecounts reaches a value at which the above-described continuous state isdetermined, the duty ratio (d) of the drive motor is increased. A valuecalculated as an increment Δd is set relatively small, and for example,may be 2%. According to this disclosed technology, they say, byperforming the above-described control, a radical increase of motortorque can be avoided even if pinching occurs, and the speed of theslide door can be made to coincide with the target speed irrespective ofa load change.

DISCLOSURE OF INVENTION

However, in the above-described technology, in the case where thepinching occurs and the actual speed of the slide door is lowered, theduty ratio of the drive motor has been increased though a value thereofhas been small. Therefore, the torque of the drive motor has beenincreased though a value thereof has been small, leading to a problem ofan inevitable increase of a pinching load.

In this connection, the present invention was created in considerationof the foregoing problem. It is an object of the present invention toprovide a control device for a vehicular opening/closing body, whichreduces a pinching load even if the speed of the opening/closing body islowered due to an occurrence of pinching.

In order to attain the foregoing object, a control device for avehicular opening/closing body includes an actual speed detecting unitfor detecting an actual opening/closing body speed which is an actualopening/closing speed of the vehicular opening/closing body provided ina vehicle, a target speed generating unit for generating a targetopening/closing body speed which is a target opening/closing speed ofthe vehicular opening/closing body, a duty ratio calculating unit forobtaining a speed difference between the target opening/closing bodyspeed generated by the target speed generating unit and the actualopening/closing body speed detected by the actual speed detecting unit,and for calculating, by use of the obtained speed difference, a dutyratio when power supplied to a motor driving to open/close the vehicularopening/closing body is subjected to duty control, and a gain settingunit for setting a gain for use in calculating the duty ratio by theduty ratio setting unit, wherein the duty ratio calculating unitcalculates the duty ratio based on an addition result obtained by addinga first multiplication value in which the speed difference is multipliedby a proportional gain and a second multiplication value in which anintegral value of the speed difference is multiplied by an integralgain, and a third multiplication value in which the actualopening/closing body speed is multiplied by a feedback gain.

According to the present invention, against radical load variations ofthe opening/closing body due to the pinching and the like, the reductionof the pinching load can be achieved by lowering the actual speed of theopening/closing body to an extent enough to avoid the influence of theload.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a diagram showing a configuration of a control device for avehicular opening/closing body according to an embodiment of the presentinvention.

FIG. 2 is a perspective view of a front face of a pulse encoder.

FIG. 3 is a perspective view of a back face of the pulse encoder.

FIG. 4 is a block diagram showing a functional configuration of a dooropening/closing control unit.

FIG. 5 is a diagram showing a configuration of a control system by anegative feedback control, including a duty ratio calculation unit,according to a first embodiment of the present invention.

FIG. 6 is a graph showing target responsiveness and responsiveness ofdisturbance with respect to an actual door speed.

FIG. 7 is a graph showing response characteristics of door speed/appliedvoltage.

FIG. 8 is a diagram showing a configuration of a control system by anegative feedback control, including a duty ratio calculation unit,according to a second embodiment of the present invention.

FIG. 9 is a diagram showing a configuration of a control system by anegative feedback control, including a duty ratio calculation unit,according to a third embodiment of the present.

FIG. 10 is a diagram showing a configuration of a control system by anegative feedback control, including a duty ratio calculation unit,according to a fourth embodiment of the present invention.

FIG. 11 is a flowchart showing a processing procedure of calculatingdoor position information.

FIG. 12 is a flowchart showing a processing procedure of calculating aduty ratio.

FIG. 13 is a flowchart showing another processing procedure ofcalculating the duty ratio.

FIG. 14 is a view showing Table 1 representing a relationship between avalue of each gain and each door opening/closing position.

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiments of the present invention will be described below withreference to the drawings.

For example, the present invention is applied to a slide door controlsystem configured as shown in FIG. 1.

This slide door control system is provided with the slide dooropening/closing system 11 for controlling drives to open/close the slidedoor 1 in a range from a half shut position (half latched position) to afully open position, and the door closure system 12 which is provided inthe slide door 11 for controlling a drive of the slide door 1 in a rangefrom the half shut position (half latched position) to a properly shutposition (full latched position).

In this slide door control system, a control domain of the slide door 1,which is controlled by the slide door opening/closing system 11, rangesfrom a position where a half shut state is detected (half latchedposition) to the fully open position. This range is equal to a rangefrom a domain out of the control of the door closure system 12 to thefully open position.

The door closure system 12 is composed by including the feedingconnector 21 connected to an unillustrated battery, the close motor 22,the release motor 23, the latch mechanism 24, the half latch switch 25,and the closure controller 26 connected to the door handle 2.

Upon detecting that the slide door 1 reaches the half latched position,the half latch switch 25 supplies a half latch detection signal to theclosure controller 26.

Meanwhile, the latch mechanism 24 is driven by torque generated by theclose motor 22. Then, the latch mechanism 24 is fastened with anunillustrated striker provided on the slide door 1 to set the slide door1 from the half shut state to the properly shut state. On the otherhand, the latch mechanism 24 is driven by torque generated by therelease motor 23. Then, the latch mechanism 24 releases the fasteningwith the unillustrated striker provided on the slide door 1 to set theslide door 1 from the properly shut state to an open state.

The closure controller 26 receives an operation input signal of the doorhandle 2, a half latch detection signal, and an operation input signalfrom the door opening/closing control unit 36, which is described later,to control the operation of latch mechanism 24. This closure controller26 detects that the slide door 1 is operated to an open state by theoperation of the door handle 2 by a user.

In addition, in the case where this closure controller 26 recognizesthat the slide door 1 is in the open state, the closure controller 26supplies power from the feeding connector 21 to the close motor 22 inresponse to the recognition that the slide door 1 reaches the halflatched position by the half latch switch 25 and in response to areceipt of a signal instructing the slide door 1 to be set in theproperly shut state. Thus, the closure controller 26 allows the closemotor 22 to generate torque. In such a way, the closure controller 26allows the latch mechanism 24 to operate, thus setting the slide door 1in the properly shut state.

Furthermore, in the case where the closure controller 26 recognizes thatthe slide door 1 is in the properly shut state, the closure controller26 supplies power from the feeding connector 21 to the release motor 23in response to a receipt of a signal from the later-described dooropening/closing operation unit 34 or keyless controller 35 through thedoor opening/closing control unit 36. Thus, the closure controller 26allows the release motor 23 to generate torque. In such a way, theclosure controller 26 allows the latch mechanism 24 to operate, thussetting the slide door 1 in the open state and locating the same slidedoor 1 in an opening direction more than the half latched position byreaction force of a weatherstrip. In this state, the slide door 1 islocated at the region controlled by the slide door opening/closingsystem 11.

The slide door opening/closing system 11 is provided with the door driveunit 31 connected to the slide door 1, the buzzer 32, the main operationunit 33, the door opening/closing operation unit 34, the keylesscontroller 35, and the door opening/closing control unit 36 forcontrolling these described units.

For example, the main operation unit 33 and the door opening/closingoperation unit 34 are disposed at positions operatable by a user aboarda vehicle. These main operation unit 33 and door opening/closingoperation unit 34 supply the operation input signals to the dooropening/closing control unit 36 in accordance with the operation by theuser.

The door opening/closing operation unit 34 is provided with a switch forgenerating the operation input signal which instructs the start of theopening operation of the slide door 1, and a switch for generating theoperation input signal which instructs the start of the closingoperation of the slide door 1. This door opening/closing operation unit34 supplies the operation input signals to the door opening/closingcontrol unit 36 in accordance with the operations of the respectiveswitches.

The main operation unit 33 is provided with a switch for generating asignal which permits and inhibits the control of the slide door controlsystem. The main operation unit 33 supplies a permission signal or aninhibition signal to the door opening/closing control unit 36 inaccordance with the operation of the unit.

The keyless controller 35 receives a radio signal transmitted from aportable remote controller by an operation of a switch provided thereon,generates an operation input signal from the radio signal, and suppliesthe generated operation input signal to the door opening/closing controlunit 36.

The buzzer 32 rings in response to a drive signal from the dooropening/closing control device 36, thus informing the user of theoperation of the slide door 1.

The door drive unit 31 includes the door connecting mechanism 41, thepulleys 42 and 43, the drum mechanism 44, the spring mechanism 45, allof which are connected through the wire 46. In addition, this door driveunit 31 includes the pulse encoder 47 for detecting the operation of thedrum mechanism 44 and generating a door drive pulse for the slide door1, the door opening/closing drive motor 48 for generating torque bywhich the slide door is driven to open/close, and the clutch mechanism49 for connecting/disconnecting the door opening/closing drive motor 48and the drum mechanism 44.

The door drive unit 31 is configured as shown in FIGS. 2 and 3, whichare perspective views partially showing front and back faces thereof. Asshown in FIG. 3, the door drive unit 31 includes the wire 46 connectedto the slide door 1, the drum mechanism 44 of which side face is woundaround by the wire 46, and the spring mechanism 45 for maintaining thewire 46 at a certain tension, all of which are housed in the case 50.When the door opening/closing drive motor 48 rotates, the drum mechanism44 rotates by torque thereof, thus winding up and releasing the wire 46.The drum mechanism 44 performs operation of winding up and releasing thewire 46, thus allowing the slide door 1 to operate in the opening orclosing direction.

Moreover, as shown in FIG. 2, as the pulse encoder 47, the door driveunit 31 includes the rotating electrode plate 51, which is connectedadjacent to the center axis of the drum mechanism 44 and has electrodesformed thereon at a predetermined interval, two rotation detectionterminals 52 in contact with the portions of the rotating electrodeplate 51, where the electrodes are formed, and the grounding terminal53. The drum mechanism 44 rotates by the torque of the dooropening/closing drive motor 48, and thus the rotating electrode plate 51is rotated, and the rotation detection terminals 52 are brought intocontact with the respective electrodes. The pulse encoder 47 generatesthe door drive pulse in response to the above-described electricalcontact. Thus, the pulse encoder 47 supplies the door drive pulse inaccordance with the opening/closing operation of the slide door 1 to thedoor opening/closing control unit 36. This door drive pulse generated bythe pulse encoder 47 has a frequency in response to the moving speed ofthe slide door 1 because the door opening/closing drive motor 48 and thepulse encoder 47 are configured to be connected adjacent to each other.Note that, though the mechanical encoder as described above has beenused in this embodiment, for example, an optical encoder and the likemay be used instead.

The door opening/closing drive motor 48 is supplied with power of whichduty ratio is controlled from the drive circuit 61 shown in FIG. 4.Then, the door opening/closing drive motor 48 generates torque inresponse to the duty ratio. Thus, the door opening/closing drive motor48 rotationally drives the drum mechanism 44 through the clutchmechanism 49, thus driving the slide door 1.

Furthermore, as shown in FIG. 4, the drive circuit 61 and the batteryvoltage detection unit 62 are connected to the door opening/closingcontrol unit 36.

The drive circuit 61 is connected to an unillustrated battery andprovided with a duty ratio signal sent from the door opening/closingcontrol unit 36 and with a control signal indicating the drive directionof the door opening/closing drive motor 48. This drive circuit 61supplies a driving current to the door opening/closing drive motor 48 inaccordance with the duty ratio signal and the control signal. Thus, thedrive circuit 61 rotationally drives the door opening/closing drivemotor 48 in the opening or closing direction of the slide door 1.

The battery voltage detection unit 62 is connected to an unillustratedin-vehicle battery, and detects a battery voltage supplied from thebattery to the drive circuit 61. This battery voltage detection unit 62supplies the detected battery voltage to the door opening/closing unit36.

FIG. 4 is a functional block diagram showing the configuration of thedoor opening/closing control unit 36. In FIG. 4, the dooropening/closing control unit 36 includes the door opening/closingoperation unit 34, the operation determination unit 71 receiving theoperation input signal from the main operation unit 33, the drivedetermination unit 72 receiving a half latching detection signal fromthe half latch switch 25, the drive direction decision unit 73, the doorposition calculation unit 74 receiving the door drive pulse from thepulse encoder 47, the speed calculation unit 75, the pinchingdetermination unit 76, the target door speed generation unit 77, theduty ratio calculation unit 78, and the feedback gain setting unit 79.

The door position calculation unit 74 receives the door drive pulse andcalculates the door position. For example, this door positioncalculation unit 74 holds a numerical value “300” as door positioninformation when the slide door 1 is located at the fully open position.Then, upon receiving the door drive pulse by the movement of the slidedoor 1 from the fully open state to the closing direction, the doorposition calculation unit 74 calculates the door position information byperforming subtraction from the numerical value “300.” This doorposition calculation unit 74 supplies the calculated door positioninformation to the pinching determination unit 76, the drivedetermination unit 72 and the target door speed generation unit 77.

The speed calculation unit 75 receives the door drive pulse from thepulse encoder 47 and calculates the cycle of the door drive pulse, andthus calculates the actual moving speed of the slide door 1 andgenerates actual moving speed information. Then, the speed calculationunit 75 supplies the generated actual moving speed information to thepinching determination unit 76, the duty ratio calculation unit 78 andthe feedback gain setting unit 79.

The pinching determination unit 76 detects pinching of a foreign objectin the slide door 1 based on the door position information and theactual moving speed information. Upon detecting the pinching of aforeign object, this pinching determination unit 76 supplies a pinchingdetection signal to the drive determination unit 72.

Upon receiving the operation input signals from the door opening/closingoperation unit 34 and the main operation unit 33, the operationdetermination unit 71 determines the operation contents of the dooropening/closing operation unit 34 and main operation unit 33, andsupplies an operation content determination signal to the drivedetermination unit 72.

The drive determination unit 72 recognizes the operation contents of theuser based on the operation content determination signal from theoperation determination unit 71. In addition, upon receiving the halflatching detection signal from the half latch switch 25, the drivedetermination unit 72 recognizes that the slide door 1 is in the halfshut state. In this half shut state, the drive determination unit 72recognizes that the position of the slide door 1 is out of the rangecontrolled by the slide door opening/closing system 1 but in the rangecontrolled by the door closure system 12. Thus, the drive determinationunit 72 comes in a state of not controlling the operation of the slidedoor 1. Furthermore, the drive determination unit 72 is connected to thedoor position calculation unit 74 and the pinching determination unit76, and provided with the door position information and the pinchingdetection signal therefrom.

The drive determination unit 72 determines the drive contents of theslide door 1 and buzzer 32 based on the received signals, and suppliesthe drive signal to the buzzer 32 and the drive content signalindicating the drive contents of the slide door 1 to the drive directiondecision unit 73.

Upon receiving, from the operation determination unit 71, the operationcontent determination signal instructing the moving direction of theslide door 1 to be inverted, the drive determination unit 72 firstsupplies a drive content signal instructing a motor brake to be appliedto the drive direction decision unit 73. Subsequently, the drivedetermination unit 72 supplies, to the drive direction decision unit 73,a drive content signal instructing the slide door 1 to be inverselymoved after the elapse of a predetermined period since the applicationof the motor brake.

The drive direction decision unit 73 determines the drive direction ofthe door opening/closing drive motor 48 in accordance with the drivecontent signal from the drive determination unit 72, and supplies thecontrol signal controlling the relay state of the drive circuit 61.

The target speed generation unit 77 stores target speeds in accordancewith the door positions as a map in advance. The target speed generationunit 77 receives the door position information from the door positioncalculation unit 74, selects a target speed as a target of the slidedoor 1 from the map in accordance with a door position, generates targetspeed information, and supplies the generated target speed informationto the duty ratio calculation unit 78 and the feedback gain setting unit79.

The feedback gain setting unit 79 sets an integral gain, a proportionalgain, a feedforward gain and the like for generating the torquenecessary for the door opening/closing drive motor 48 based on thebattery voltage detection signal, the door position information, thetarget speed, and the actual moving speed. Then, the feedback gainsetting unit 79 supplies the set gain to the duty ratio calculation unit78.

The duty ratio calculation unit 78 performs an arithmetic operation tobe described later so as to set the actual door speed at the target doorspeed based on the respective gains set by the feedback gain settingunit 79.

Then, the duty ratio calculation unit 78 generates a duty cycle signalindicating a duty ratio at which the torque necessary for the dooropening/closing drive motor 48 is generated, and supplies the generatedduty cycle signal to the drive circuit 61.

FIG. 5 is a diagram showing a configuration of a control systemincluding the duty ratio calculation unit 78 according to the firstembodiment of the present invention, the control system performingnegative feedback control based on a speed difference between the targetdoor speed VL and the actual door speed V. In FIG. 5, the duty ratiocalculation unit 78 includes the first adder 81 receiving the targetdoor speed and a negative value of the actual door speed, theproportional gain operational unit 82, the integration operational unit83, the integral gain operational unit 84, and the second adder 85adding the output of the proportional gain operational unit 82 and theoutput of the integral gain operational unit 84 to supply the duty cyclesignal indicating the duty ratio. In the duty ratio calculation unit 78,the proportional gain of the proportional gain operational unit 82 andthe integral gain of the integral gain operational unit 84 are set bythe feedback gain setting unit 79. In FIG. 5, the duty cycle signalsupplied from the second adder 85 is provided to the door control model86, and thus the actual door speed V is obtained. This door controlmodel 86 is represented so as to be approximated to an expression (1) tobe described later.

When the target door speed and the actual door speed are provided to theduty ratio calculation unit 78, the actual door speed is subtracted fromthe target door speed by the first adder 81. A result of the subtractionis integrated by the integration operational unit 83, and is multipliedby a negative proportional gain (K2) by means of the proportional gainoperational unit 82. The output of the integration operational unit 83is multiplied by an integral gain (K1) by means of the integral gainoperational unit 83. A result of the multiplication is added to theoutput of the proportional gain operational unit 82 in the second adder85. A result of the addition is supplied as the duty cycle signal to thedrive circuit 61.

In the first embodiment of the present invention, the duty ratiocalculation unit 78 described above is provided. Thus, when the actualdoor speed V is lowered more than the target door speed VL, the dutyratio is not increased by a value proportional to (VL-V), but the dutyratio is reduced. Specifically, in the case of configuring the controlsystem performing usual negative feedback control as shown in FIG. 5, inwhich a predetermined gain is multiplied by the difference between thetarget door speed VL and the actual door speed V, a negative value isused for the proportional gain K2 in place of a positive value for usein usual control. The first embodiment of the present invention ischaracterized in this matter.

When the proportional gain K2 is set negative, it is impossible that theactual door speed V coincides with the target door speed VL forvariations of a load. Therefore, in the duty ratio calculation unit 78shown in FIG. 5, the value obtained by integrating (VL-V) by theintegration operational unit 83 is multiplied by the predeterminedintegral gain K1. A value obtained by the multiplication is added to thevalue obtained by multiplying (VL-V) by the negative proportional gainK2.

In the case where the actual door speed is radically lowered due to theoccurrence of pinching and the like, the duty ratio is reduced inproportion to the lowering of the actual door speed owing to the effectof the negative proportional gain K2. Thus, the lowering of the actualdoor speed is accelerated, thus making it possible to attain asignificant lowering of the pinching load. Meanwhile, for a load whichis increased/decreased because the vehicle is located on a slope and soon, the integral value is sufficiently increased with the elapse of timesince such a load is not a load radically varied. In such a way, themotor torque is increased, and the actual door speed V is made tocoincide with the target door speed VL.

Next, in the door opening/closing control unit 36 configured as above,the responsiveness of the door opening/closing drive motor 48 by therespective gains set in the duty ratio calculation unit 78 will bedescribed.

When the door opening/closing drive motor 48 to be controlled is adirect current motor, a relationship between a battery voltage suppliedfrom the drive circuit 61 and the actual moving speed is approximated(modeled) as characteristics of a first-order lag as represented in thefollowing Expression 1.a/(s+τ)  (1)where τ is a constant, and a is also defined as a constant forsimplifying the explanation though this a is a function depending on abattery voltage subjected to duty control. Specifically, the actual doorspeed in a stationary state is proportional to the ratio of duty appliedto the door opening/closing drive motor 48.

As shown in FIG. 5, the duty ratio calculation unit 78 configures a PI(proportional-integral) control system. For example, if the controlsystem has the integral gain K1 equal to 1 and the proportional gain K2equal to 1 and the door control model represented by Expression 1 has τequal to 1 and a equal to 1, then responsiveness thereof to the targetvalue and responsiveness to a disturbance, that is, to the pinching, areshown by the circled number 1 of FIG. 6. FIG. 6 is a graph showing anactual door speed in the case where the door starts to move from astopped state and a disturbance (pinching) occurs in fifteen secondsfrom the start of movement. The responsiveness shown by the circlednumber 1 of FIG. 6 is one representing characteristics in which a closedloop pole ω given by the following Expression 2 becomes 1. The dampingcoefficient ζ is given by the following Expression 3.ω²=K1  (2)ζ=(τ+K2)/(2×ω)  (3)

Here, as ω becomes smaller and smaller, the responsiveness to thedisturbance is lowered. Specifically, it takes more time for the actualdoor speed to be recovered by overcoming the disturbance. Therefore,when the integral gain K1 and the proportional gain K2 are selected soas to obtain characteristics, for example, in which ω becomes equal to0.5, K1 becomes equal to 0.25 and K2 becomes equal to 0 by theabove-described Expressions (2) and (3). Note that a too small dampingcoefficient ζ brings a vibratory response and a too large dampingcoefficient ζ brings a too dull response. Therefore, Expression (3) issolved under the condition where ζ becomes equal to 1.

Characteristics in this case become as shown by the circled number 2 ofFIG. 6. Furthermore, if ω is set equal to 0.4, then K2 cannot help beingset at a negative value, that is, −0.2 as given by the foregoingExpression (3). Hence, when K2 is set equal to −0.2 and K1 is set equalto 0.16, as shown in FIG. 7, the voltage in the case where ω is setequal to 1 is raised immediately after the occurrence of the pinching asshown by the line a of FIG. 7. This raised voltage will increase thepinching load. On the other hand, when ω is set equal to 0.4, thevoltage is gradually increased after being lowered once, thus making itpossible to contribute to the lowering of the pinching load as shown bythe line b of FIG. 7.

In the first embodiment described above, the proportional gain K2 forthe difference between the target door speed VL and the actual doorspeed V is set negative, and the integral gain K1 for the integral valueof the difference therebetween is set positive. In such a way, for theradical load variations due to the pinching and the like, the door driveforce is positively reduced, and the lowering of the actual door speed,which is more than the influence of the load, is realized, thus makingit possible to attain the reduction of the pinching load. Meanwhile, itis possible to realize a door control system capable of making theactual door speed V coincide with the target door speed VL for thegentle load variations due to a slant of the vehicle, variations infrictional force of a door rail and the like.

FIG. 8 is a diagram showing a configuration of a control system, whichincludes the duty ratio calculation unit 78 according to a secondembodiment of the present invention, and is similar to that of FIG. 5.In FIG. 8, this duty ratio calculation unit 78 includes the first adder81 receiving the target door speed and a negative value of the actualdoor speed, the proportional gain operational unit 87, the integrationoperational unit 83, the integral gain operational unit 84, the secondadder 85, and the feedback gain operational unit 88. In this duty ratiocalculation unit 78, the proportional gain of the proportional gainoperational unit 82, the integral gain of the integral gain operationalunit 84, and the feedback gain of the feedback gain operational unit 88are set by the feedback gain setting unit 79.

When the target door speed VL and the actual door speed V are providedto the duty ratio calculation unit 78, the actual door speed issubtracted from the target door speed by the first adder 81. A result ofthe subtraction is integrated by the integration operational unit 83,and is multiplied by the positive proportional gain K2 by means of theproportional gain operational unit 87. The output of the integrationoperational unit 83 is multiplied by the integral gain K1 by means ofthe integral gain operational unit 84. The actual door speed ismultiplied by the feedback gain K4 by means of the feedback gainoperational unit 88. Results of the multiplications in the proportionalgain operational unit 87, the integral gain operational unit 84 and thefeedback gain operational unit 88 are added in the second adder 85, anda result of the addition is supplied as the duty cycle signal to thedrive circuit 61.

In such a configuration as described above, the second embodiment ischaracterized in that the duty ratio is increased/decreased inproportion to the actual door speed by use of a value obtained bymultiplying the actual door speed V by the positive feedback gain K4,thus obtaining an effect similar to that of the first embodimentmentioned above. In the first embodiment mentioned above, in the casewhere the actual door speed V is lowered, the duty ratio is controlledso as to be lowered instantaneously and then increased. In such acontrol method, follow-up capability is not preferable for the targetdoor speed VL.

Accordingly, in this embodiment, the value proportional to the actualdoor speed V is subjected to the feedforward, and the proportional gainK2 and the integral gain K1, which are positive values, are used. Thus,it is possible to obtain a control system capable of operating for theload variations in a similar way to that of the first embodimentmentioned above and of following the change of the target door speedwell.

The second embodiment described above can obtain a similar effect evenif a configuration shown in FIG. 9 (third embodiment) is adopted. Incomparison with the configuration shown in FIG. 8, in the configurationshown in FIG. 9, the feedback gain operational unit 88 shown in FIG. 8is deleted, the feedforward gain operational unit 89 for multiplying thetarget door speed VL by the feed forward gain K3 is provided, and theproportional gain operational unit 90 for multiplying the additionresult of the first adder 81 by the proportional gain K2 is provided inplace of the proportional gain operational unit 87. In addition,multiplication results in the feedforward gain operational unit 89, theproportional gain operational unit 90 and the integral gain operationalunit 84 are added in the second adder 85. Here, the respective gainsshown in FIGS. 8 and 9 are converted as represented in the followingExpressions (4) and (5). Thus, the control system configured as shown inFIG. 8 and the control system configured as shown in FIG. 9 becomeequivalent to each other.K2=K5−K4  (4)K3=K4  (5)

The control system having the configuration shown in the thirdembodiment in FIG. 9 is compared with the control system shown in thefirst embodiment in FIG. 5. Then, in the control system of the firstembodiment, when the proportional gain K2 is set at −0.2, theresponsiveness to the target value at the start of movement of the doorbecomes slow as in the case where the proportional gain K2 is set at 0(as shown by the circled number 2 of FIG. 6). Besides the above, theactual door speed follows up the target door speed after the door movesin the reverse direction once. Therefore, the responsiveness at thestart of the movement has been deteriorated.

As an example of the embodiment for avoiding this problem, feedforwardis considered to be performed by use of the feedforward gain K3 employedin the embodiment shown in FIG. 9. For example, in the case where thefeedback gain is set equal to 0.7, the proportional gain K2 is set equalto 0.5, and the integral gain K1 is set equal to 0.16, theresponsiveness becomes as shown by the circled number 4 of FIG. 6. Inthe response characteristics shown by the circled number 4 of FIG. 6,though the responsiveness to the disturbance is completely the same asthat of the circled number 3 of FIG. 6, the responsiveness of the targetvalue at the start of the movement becomes approximate to theresponsiveness shown by the circled number 1 of FIG. 6.

FIG. 10 is a diagram showing a configuration of a control system, whichincludes the duty ratio calculation unit 78 according to a fourthembodiment of the present invention, and is similar to that of FIG. 5.In comparison with the duty ratio calculation unit 78 of the firstembodiment shown in FIG. 5, the duty ratio calculation unit 78 in FIG.10 is characterized by including a prepositioned compensator providedwith the compensator 91, which supplies the target door speed VL to thefirst adder 81 in response characteristics to be described below, andfunctions as a target speed changing unit, and provided with thecompensator 92, which supplies the target door speed VL to the secondadder 85 in response characteristics to be described below, andfunctions as a compensation unit.

Assuming that responsiveness to a desired target value is obtained as atransfer function (s), the transfer function A(s) of the compensator 91is represented as in the following Expression (6), and the transferfunction B(s) of the compensator 92 is represented as in the followingExpression (7).A(s)=m(s)  (6)B(s)={(s+τ)/a}×m(s)  (7)

In the configuration as described above, even if the integral gain K1and the proportional gain K2 are set at arbitrary values, for example,even if the proportional gain K2 is set at a negative value, desiredresponse characteristics to the target value are obtained. Consequently,the speed of the door can be lowered at the time of pinching, and thetarget door speed can be followed up well.

Next, the processing procedure when the integral gain K1, theproportional gain K2, the feed forward gain K3 and the proportional gainK5 are set by the above-mentioned door opening/closing control unit 36to generate the duty cycle signal in the third embodiment will bedescribed with reference to FIGS. 11, 12 and 13.

First, the door opening/closing control unit 36 performs processing ofthe flowchart shown in FIG. 11 in the door position calculation unit 74,thus calculating the moving direction and the door position of the slidedoor 1. Subsequently, the door opening/closing control unit 36 performsprocessing of the flowchart shown in FIG. 12 or 13, thus generating theduty cycle signal.

Next, a method for calculating the door position by the door positioncalculation unit 74 will be described with reference to FIG. 11.

In FIG. 11, when the slide door 1 actually moves and a door drive pulseis provided from the pulse encoder 47, a count value (FreeRun) of aninternal free run counter is set at a current count value (CountNow) bythe door position calculation unit 74 (Step S1101). For example, thisfree run counter is one counting the number of pulses by detecting risesof the door drive pulses from the pulse encoder 47.

Next, a difference between the previous count value and the currentcount value set in Step S1101 is operated by the door positioncalculation unit 74, a value obtained by the operation is set as a pulsevalue (Pulse) for obtaining the door position, and the current countvalue obtained in Step S1101 is changed to a previous count value (StepS1102). Then, it is determined whether or not the pulse value obtainedby the operation in Step S1102 is a negative value smaller than “0”(Step S1103). When the pulse value is determined not to be smaller, thecount value is used as it is in processing that follows. When the pulsevalue is determined to be smaller, the maximum count value of the freerun counter (MAXFREERUN) and the count value obtained in Step S1102 areadded together, and a value obtained by the addition is set as a countvalue to be used in the processing that follows (Step S1104).

Next, a voltage level of the B phase of the door opening/closing drivemotor 48 is determined by the door position calculation unit 74 todetermine the rotation direction of the door opening/closing drive motor48 (Step s1105). In this case, the door position calculation unit 74determines whether or not the voltage level of the B phase of the dooropening/closing drive motor 48 is a high level. When it is determinedthat the voltage level is not high, the door count value is increased by“1” (Step S1106). When it is determined that the voltage level is high,the door counter value (DoorCount) indicating the moving direction ofthe slide door 1 is decreased by “1” (Step S1107).

Next, a value of an edge flag (edgeflag) indicating whether or not thedoor drive pulse is provided is set at “1” to tell that the pulse isprovided (Step S1108). Then, a position (area) where the slide door 1 ispresent is calculated based on the pulse value obtained by the operationin Step S1102 or S1104 and the rotation direction of the dooropening/closing drive motor 48, which is determined in Step S1105, andthe door position information thus calculated is supplied to the targetspeed generation unit 77 and the feedback gain setting unit 79 (StepS1109).

In such a way, the calculated door position information is provided tothe target speed generation unit 77 and the feedback gain setting unit79. Furthermore, processing shown in FIG. 12 is started in apredetermined cycle when the processing is executed (for example, every50 msec).

FIG. 12 is a flowchart showing a procedure in the case of realizingprocessing of generating the duty cycle signal according to a fifthembodiment of the present invention by, for example, a microcomputer.

In FIG. 12, first, an operation of (1000×2.7 (electrode interval)/pulsewidth of encoder) is performed in the speed calculation unit 75, and theactual door speed V is obtained (Step S1201). Note that theabove-described calculation expression for the actual door speed V is amere example and can be changed appropriately in accordance with theelectrode interval of the encoder and the like. Subsequently, the targetdoor speed VL corresponding to the door position calculated by the doorposition calculation unit 74 in the above-described manner is generatedin the target speed generation unit 77 and supplied to the duty ratiocalculation unit 78 (Step S1202).

Next, the actual door speed V and the target door speed VL are comparedwith each other in the feedback gain setting unit 79 (Step S1203). If Vis equal to/larger than VL, then, for example, the integral gain K1 isset equal to 1, the proportional gain K2 is set equal to 1, and thefeedback gain K3 is set equal to 0 (Step S1204). If V is smaller thanVL, then, for example, the integral gain K1 is set equal to 0.16, theproportional gain K2 is set equal to −0.2, and the feedback gain K3 isset equal to 0.75 (Step S1205). Subsequently, in the duty ratiocalculation unit 78, the target door speed VL is multiplied by thefeedback gain K3 (Step S1206), (VL-V) is multiplied by the proportionalgain K2 (Step S1207), and (VL-V) is multiplied by the integral gain K1(Step S1208). Then, the duty ratio calculation unit 78 adds, by thesecond adder 85, a result of the multiplication (F) obtained in StepS1206, a result of the multiplication (P) obtained in Step S1207 and anintegral value (Isum) of a result of the multiplication (I) obtained inStep S1208. Thus, the duty ratio calculation unit 78 obtains the dutyratio (Duty) (Step S1209).

Next, the duty ratio calculation unit 78 determines whether or not theduty ratio obtained in Step S1209 is 0% or more (Step S1210). When theduty ratio is determined to be 0% or more, the processing proceeds toStep S1212. When the duty ratio is determined not to be 0% or more, theduty ratio is set at 0%.

Next, the duty ratio calculation unit 78 determines whether or not theduty ratio obtained in Step S1209 is 100% or more. Specifically, it isdetermined whether or not the actual door speed V exceeds the targetdoor speed VL. When the duty ratio is determined to be 100% or more, theprocessing proceeds to Step S1214. When the duty ratio is determined notto be 100% or more, the multiplication value (I) obtained in Step S1208is added to the integral value (Isum), and thus a new integral value isobtained (Step S1213). Finally, the duty ratio calculation unit 78 setsthe duty ratio of the integral value obtained in Step S1213 in aregister for driving a motor (unillustrated) of the drive circuit61(S1214).

In the above-described processing procedure shown in FIG. 12, thefeedback gain setting unit 79 sets the proportional gain K2 at apositive value in the case where the actual door speed V exceeds thetarget door speed VL, that is, in the case where (VL-V) is negative. Inaccordance with the set proportional gain K2, the integral gain K1 andthe feedback gain K3 are set. Thus, the duty ratio is reduced rapidly asusual feedback control, thus making it possible to attain the loweringof the actual door speed V. Consequently, for example, when the vehicleis stopped on a downhill slope, in the case where the actual door speedexceeds the target door speed, and in the case where the actual doorspeed is slightly lowered than the target door speed due to swingresistance, the actual door speed can be made to follow up the targetdoor speed rapidly.

FIG. 13 is a flowchart showing a procedure in the case of realizingprocessing of generating the duty cycle signal according to a sixthembodiment of the present invention by, for example, a microcomputer.This processing procedure is characterized in the following pointsincluding a replacement for the processing procedure shown in FIG. 12.Specifically, Step S1301 of setting the integral gains K1, theproportional gains K2 and the feedforward gains K3 based on the doorpositions, the actual door speeds and the target door speeds by use ofTable 1 shown in FIG. 14 is performed in place of the processing ofSteps S1203, S1204 and S1205 shown in FIG. 12.

In Table 1 shown in FIG. 14, the integral gains K1, the proportionalgains K2 and the feedback gains K3 are set in accordance with the doorpositions (10 mm, 300 mm, 600 mm) with the properly shut position takenas a reference and magnitude relationships (VL-V≦−2,−2<VL-V & VL-V<10,10<VL-V) between the actual door speeds V and the target door speeds VL.

In the processing shown in FIG. 13, as shown in Table 1 of FIG. 14, allof the integral gains K1, the proportional gains K2 and the feedbackgains K3 are changed in accordance with the values of (VL-V) and thedoor positions. Thus, the proportional gain K2 is set negative only whenthe pinching occurs and the value of (VL-V) is significantly increased,and thus the actual door speed V is lowered positively. Furthermore, inthe case where the value of (VL-V) is small in both positive andnegative, the actual door speed V can be made to coincide with thetarget door speed VL rapidly while setting the proportional gain K2positive. Moreover, not only the proportional gain K2 but also theintegral gain K3 is set at the optimum value for the value of theproportional gain K2. Therefore, for convergence characteristics to thetarget door speed VL, desired characteristics, for example, criticalbraking characteristics, can be used. In addition, the change of thegains depending on the door position enables the gains to be changed,for example, at a door position where the pinching may occur and at adoor position where the pinching may not occur. Thus, appropriatecontrol can be performed.

Note that, in the sixth embodiment described above, though all of theintegral gain K1, the proportional gain K2 and the feedforward gain K3are decided on the basis of the opening/closing position of the door, itis satisfactory that at least one gain is selected from the gainsdescribed above.

Moreover, in the embodiments described with reference to the flowchartsof FIGS. 12 and 13, the gains K1, K2 and K3 are set on the basis of thedoor position, the door speed and the target door speed. However, in thecase of configuring the control system as shown in FIG. 8, it issatisfactory that the gains K1, K4 and K5 are set in place of the gainsK1, K2 and K3.

As described above, according to the present invention, the actual speedof the opening/closing body is lowered to an extent enough to reduce theinfluence of the load, thus making it possible to attain the reductionof the pinching load.

Japanese Patent Application No. 2002-241845, filed on Aug. 22, 2002, isincorporated herein by reference in its entirety.

1. A control device for a vehicular opening/closing body, comprising: an actual speed detecting unit for detecting an actual opening/closing body speed which is an actual opening/closing speed of the vehicular opening/closing body provided in a vehicle; a target speed generating unit for generating a target opening/closing body speed which is a target opening/closing speed of the vehicular opening/closing body; a duty ratio calculating unit for obtaining a speed difference between the target opening/closing body speed generated by the target speed generating unit and the actual opening/closing body speed detected by the actual speed detecting unit, and for calculating, by use of the obtained speed difference, a duty ratio when power supplied to a motor driving to open/close the vehicular opening/closing body is subjected to duty control; and a gain setting unit for setting a gain for use in calculating the duty ratio by the duty ratio setting unit, wherein the duty ratio calculating unit calculates the duty ratio based on an addition result obtained by adding a first multiplication value in which the speed difference is multiplied by a negative proportional gain, and a second multiplication value in which an integral value of the speed difference is multiplied by an integral gain.
 2. The control device for a vehicular opening/closing body according to claim 1, wherein the gain setting unit sets the proportional gain at a negative value only when the speed difference is equal to a predetermined value or more.
 3. A control device for a vehicular opening/closing body, comprising: an actual speed detecting unit for detecting an actual opening/closing body speed which is an actual opening/closing speed of the vehicular opening/closing body provided in a vehicle; a target speed generating unit for generating a target opening/closing body speed which is a target opening/closing speed of the vehicular opening/closing body; a duty ratio calculating unit for obtaining a speed difference between the target opening/closing body speed generated by the target speed generating unit and the actual opening/closing body speed detected by the actual speed detecting unit, and for calculating, by use of the obtained speed difference, a duty ratio when power supplied to a motor driving to open/close the vehicular opening/closing body is subjected to duty control; and a gain setting unit for setting a gain for use in calculating the duty ratio by the duty ratio setting unit, wherein the duty ratio calculating unit calculates the duty ratio based on an addition result obtained by adding a first multiplication value in which the speed difference is multiplied by a proportional gain, a second multiplication value in which an integral value of the speed difference is multiplied by an integral gain, and a third multiplication value in which the actual opening/closing body speed is multiplied by a positive feedback gain.
 4. A control device for a vehicular opening/closing body, comprising: an actual speed detecting unit for detecting an actual opening/closing body speed which is an actual opening/closing speed of the vehicular opening/closing body provided in a vehicle; a target speed generating unit for generating a target opening/closing body speed which is a target opening/closing speed of the vehicular opening/closing body; a duty ratio calculating unit for obtaining a speed difference between the target opening/closing body speed generated by the target speed generating unit and the actual opening/closing body speed detected by the actual speed detecting unit, and for calculating, by use of the obtained speed difference, a duty ratio when power supplied to a motor driving to open/close the vehicular opening/closing body is subjected to duty control; and a gain setting unit for setting a gain for use in calculating the duty ratio by the duty ratio setting unit, wherein the duty ratio calculating unit calculates the duty ratio based on an addition result obtained by adding a first multiplication value in which the speed difference is multiplied by a proportional gain, a second multiplication value in which an integral value of the speed difference is multiplied by an integral gain, and a third multiplication value in which the target opening/closing body speed is multiplied by a positive feedback gain.
 5. The control device for a vehicular opening/closing body according to claim 1, further comprising a prepositioned compensator including a target speed conversion unit and a compensation unit, the target speed conversion unit receiving the target opening/closing body speed and supplying the target opening/closing body speed in predetermined response characteristics, and the compensation unit supplying a value calculated on the basis of the target opening/closing body speed such that the predetermined characteristics are realized, wherein the duty ratio calculating unit calculates the first multiplication value and the second multiplication value based on a speed difference between the target speed supplied from the target speed conversion unit and the actual opening/closing body speed, and calculates the duty ratio by adding an output of the compensation unit to a result of the calculation for the first multiplication value and the second multiplication value.
 6. The control device for a vehicular opening/closing body according to claim 1, further comprising a position detecting unit for detecting an opening/closing position of the opening/closing body, wherein the gain setting unit sets at least one of the integral gain and the proportional gain based on the opening/closing position of the opening/closing body, the position being detected by the position detecting unit.
 7. The control device for a vehicular opening/closing body according to claim 3, further comprising a position detecting unit for detecting an opening/closing position of the opening/closing body, wherein the gain setting unit sets at least one of the integral gain, the proportional gain and the positive feedback gain based on the opening/closing position of the opening/closing body, the position being detected by the position detecting unit.
 8. The control device for a vehicular opening/closing body according to claim 1, further comprising a position detecting unit for detecting an opening/closing position of the opening/closing body, wherein the target speed generating unit generates the target speed based on the opening/closing position detected by the position detecting unit.
 9. A control device for a vehicular opening/closing body, comprising: actual speed detecting means for detecting an actual opening/closing body speed which is an actual opening/closing speed of the vehicular opening/closing body provided in a vehicle; target speed generating means for generating a target opening/closing body speed which is a target opening/closing speed of the vehicular opening/closing body; duty ratio calculating means for obtaining a speed difference between the target opening/closing body speed generated by the target speed generating means and the actual opening/closing body speed detected by the actual speed detecting means, and for calculating, by use of the obtained speed difference, a duty ratio when power supplied to a motor driving to open/close the vehicular opening/closing body is subjected to duty control; and gain setting means for setting a gain for use in calculating the duty ratio by the duty ratio setting means, wherein the duty ratio calculating means calculates the duty ratio based on an addition result obtained by adding a first multiplication value in which the speed difference is multiplied by a negative proportional gain, and a second multiplication value in which an integral value of the speed difference is multiplied by an integral gain. 